Fong, nearly 60, chronically suffered from a number of minor discomforts, such as pains and aches in her waist and back, but was unwilling to seek medical consultations. She always dealt with the discomforts with over-the-counter (OTC) drugs only for the sake of her own convenience.

Earlier this year, Fong suddenly found her vision became blurred with redness in her eyes. She thought she had suffered from influenza, thus buying some OTC drugs from a pharmacy for consumption. In addition, as the redness in her eyes persisted, eyewash was also purchased. Two days later, however, the condition of her eyes got worse, and pain had even spread all over her head, making her feel terribly sick with nausea and vomiting.

Despite her decent tolerance, Fong felt the pain unbearable this time and decided to seek consultation from an ophthalmologist. Upon her arrival at hospital, glare began to appear in her sight.

Vision could be lost due to delayed treatment

After checkup, acute glaucoma, rather than conjunctivitis, was diagnosed, and that could permanently damage her sight and even cause total blindness if treatment was further delayed. Out of curiosity, Fong asked, "The eyes of patients with glaucoma should turn green, shouldn’t they?* Now mine are red. How is acute glaucoma possible?"

There is a common misconception that glaucoma turns its patients’ eyes green. However, that “green” actually results from the cloudy centre of an eye which is caused by cellular swelling inside the cornea. The symptom may be absent from some glaucoma cases, in particular those of acute glaucoma, whose patients may not be aware of any abnormality with their eyes in normal circumstance but their eyes could become painful and red all of a sudden with a blurred vision. Other possible symptoms include seeing rainbows or halos around objects under light, nausea and vomiting and headache.

Glaucoma results from ocular hypertension which causes damages to optic nerves and consequently leads to gradual visual impairments. It can be divided into two main types, namely open-angle glaucoma and closed-angle glaucoma. Most glaucoma cases are identified as open-angle glaucoma. In some of the cases, patients’ optic nerves are pressed because of ocular hypertension, while blockage in capillaries is the reason for some other cases. Open-angle glaucoma has two categories, i.e. primary glaucoma and secondary glaucoma. The latter is a consequence of other ophthalmic diseases. The majority of open-angle cases are chronic, in which there usually lack significant symptoms at the early stage until impairments in the visual field and sight are found when the condition is already severe. Therefore, timely treatments are critical.

Closed-angle glaucoma is caused by increased ocular pressure due to a narrowed drainage angle at the root of iris. As time passes by, optic nerve fibres shrink out of the compression. In addition to primary and secondary types, closed-angle glaucoma has acute and chronic forms. Usually, the latter does not show obvious symptoms, and is thus hardly noticeable until it develops into a later stage.

The majority of patients with acute closed-angle glaucoma are middle aged Chinese females, and their symptoms are usually apparent, including pain and redness in the eye, blurred vision, headache and vomiting. Besides, their eye pressures could surge in a short period of time to, for instance, 40–70 mm Hg from the normal level at 21 mm Hg or below. As Fong’s case belonged to the closed-angle type, it would cause permanent damages and even lead to blindness if her eye pressure was not reduced in a few hours’ time.

The best method for identifying glaucoma is regular ophthalmic checkups. General clinical diagnoses include tonometry, gonioscopy, fundal examination (which aims to check the optic nerve fibre via the pupil), visual field test (which measures the degree of damage of the patient’s peripheral vision) and optical coherence tomography (OCT), used to measure the thickness of the nerve fibre layer.

Generally speaking, people who are aged over 40, with a family history of glaucoma, long-sightedness and relatively small eyeballs, as well as having a shallow anterior chamber are exposed to higher risks of glaucoma. If the bout of the disease happens in either eye, the other is also at risk. In such circumstance, gonioscopic examination is recommended, and if it is identified as a closed-angle case, prevention of glaucoma from developing is achievable by laser iridotomy.

In pacifying, the attending doctor said acute glaucoma was curable by timely treatments, which normally began with prescribed oral medicines or injectables, or releasing a patient’s ocular pressure with eyedrops before laser surgery was operated. Since the medicines could only reduce the pressure temporarily, the laser operation was irreplaceable and, given its high success rate of immediately reducing ocular hypertension, it was highly recommended that patients with acute glaucoma should undergo the surgery as soon as possible.

Fong was nervous again of the advice on surgery. Her doctor added that there were different kinds of laser operation which could help improve a closed-angle condition to lessen eye pressure. Having said that, the doctor also reminded that the surgery was aimed to retain the sight and visual field as much as possible, but whether the already impaired sight could be improved was no guarantee. For patients with chronic closed-angle glaucoma, they might choose the cataract extraction and artificial lens insertion operation, which simultaneously removed the cataract and reduced ocular pressure by adjusting the drainage angle of the anterior chamber.

The detailed explanation calmed and convinced Fong, who underwent a laser surgery afterwards as instructed. Since then, she has showed a very satisfactory rehabilitation progress. Once she came across any suspicious ocular symptoms, she would seek medical consultation at once, and that has helped her keep a pair of healthy eyes and a sound vision up till now.

* The Chinese term of glaucoma is "青光眼". "青光" literally means "green light" in the Chinese language.